diff --git a/source/opt/type_manager.cpp b/source/opt/type_manager.cpp
index ed8a13c7..8a125278 100644
--- a/source/opt/type_manager.cpp
+++ b/source/opt/type_manager.cpp
@@ -204,7 +204,7 @@ void TypeManager::AttachIfTypeDecoration(const ir::Instruction& inst) {
         data.push_back(inst.GetSingleWordOperand(i));
       }
       if (Struct* st = target_type->AsStruct()) {
-        st->AddMemeberDecoration(index, std::move(data));
+        st->AddMemberDecoration(index, std::move(data));
       } else {
         SPIRV_UNIMPLEMENTED(consumer_, "OpMemberDecorate non-struct type");
       }
diff --git a/source/opt/types.cpp b/source/opt/types.cpp
index 285c1488..1d8cad24 100644
--- a/source/opt/types.cpp
+++ b/source/opt/types.cpp
@@ -220,8 +220,8 @@ Struct::Struct(const std::vector<Type*>& types) : element_types_(types) {
   }
 }
 
-void Struct::AddMemeberDecoration(uint32_t index,
-                                  std::vector<uint32_t>&& decoration) {
+void Struct::AddMemberDecoration(uint32_t index,
+                                 std::vector<uint32_t>&& decoration) {
   if (index >= element_types_.size()) {
     assert(0 && "index out of bound");
     return;
diff --git a/source/opt/types.h b/source/opt/types.h
index a46e4114..fb106154 100644
--- a/source/opt/types.h
+++ b/source/opt/types.h
@@ -262,7 +262,9 @@ class Struct : public Type {
   Struct(const std::vector<Type*>& element_types);
   Struct(const Struct&) = default;
 
-  void AddMemeberDecoration(uint32_t index, std::vector<uint32_t>&& decoration);
+  // Adds a decoration to the member at the given index.  The first word is the
+  // decoration enum, and the remaining words, if any, are its operands.
+  void AddMemberDecoration(uint32_t index, std::vector<uint32_t>&& decoration);
 
   bool IsSame(Type* that) const override;
   std::string str() const override;